Silicon Valley / San Jose Business Journal -- An 11th-hour attempt to extend a key patent could cost companies — including a small Fremont cardiovascular catheter maker — millions in potential revenue.

Abbott Laboratories’ cardiovascular systems unit asked the Patent and Trademark Office in July to extend a patent for “rapid-exchange” angioplasty catheters beyond its Oct. 29 expiration to May 2011.

But companies like tiny AngioScore Inc. suggest that Abbott simply wants to maintain a stranglehold on the most common method of threading stents into arteries during an angioplasty procedure.

“This is about extending a monopoly for three years that has no right to be extended,” said AngioScore President and CEO Tom Trotter.

Allowing the patent to expire would help AngioScore add millions of dollars in annual sales, Trotter said. The privately held company does not disclose annual revenue publicly, Trotter said, but the company claims its catheters have been used in more than 15,000 procedures worldwide.

Blocking the extension of the patent also would benefit giant medical equipment maker Medtronic Inc. of Minneapolis, whose chief executive told analysts in August that access to the patents would have “some upside.”

Abbott’s Xience V product — which delivers a drug-coated stent via a coronary catheter — was approved July 2 by the FDA. Such drug-eluting stents help to prevent arteries from narrowing again following an angioplasty.

Abbott also has a bare-metal stent that uses the same rapid-exchange technology, developed by Stanford University bioengineering professor Dr. Paul Yock. The technology allows for a shorter guidewire for the stent that can be manipulated by a single doctor.

AngioScore, a five-year-old company, sells rapid-exchange catheters abroad, where the patent coverage isn’t as strict, but domestically sells older “over-the-wire” products that require two physicians because the long guidewire must travel the entire length of a balloon-tipped catheter shaft.

Abbott licenses the technology to Boston Scientific and Johnson & Johnson. Together, the three companies’ rapid-exchange systems account for about 70 percent of the heart catheter market.

Abbott, based near Chicago, claims the patent extension is needed to compensate it for the lost commercial value of Xience while it was in the FDA review process.

Yock joined Abbott in its patent extension request.

The patent, known as Yock 233, was granted in 1994. Abbott acquired the patent about three years ago.

“We believe we are entitled to this extension in accordance with U.S. patent laws based on the regulatory review period associated with Xience V and are confident in the validity of our request for a patent term extension,” Abbott spokesman Jonathon Hamilton said, reading a company statement.

Townsend and Townsend and Crew LLP lawyer James Heslin, on behalf of AngioScore, said in an Aug. 21 petition to the FDA that the technology does not specify its use for delivering stents or drug-coated stents. As a result, the patent should not be eligible for patent term extension on the basis of Xience’s approval, Heslin said.

“You’ve got a very old patent that’s very close to expiration and now there’s an attempt by Big Pharma to find a way to extend the life of that patent for three more years,” Trotter said. “This is Abbott being very clever and very slick.

“They’ve had their day. Let’s follow the rules and let everybody else have their chance,” Trotter said. “There’s just a question of basic fairness here.”